[blasterjeff151]

I want to also mention an SRS site that has gotten really polished and isn't nearly as well known as Quizlet and Memrise and the rest - and it's not open source - but the science and the polish are all there (you can even create cards while watching a Youtube video and it will link to that spot in the video as an optional source reference) - it's called iDoRecall.com, worth checking out. (I found it in an old thread here on Hacker News where the creator posted about it when it was new - I followed the link and was stunned at how polished it had become)